How Much Does Iris Dena Cost?

Last updated on March 10, 2026 | Written by Alec Pow
This article was researched using 11 sources. See our methodology and corrections policy.

IRIS Dena is a Mowj-class frigate in the Islamic Republic of Iran Navy (IRIN), a state-built surface combatant that appears in open-source coverage of long deployments and port visits. Any dollar figure attached to it is a proxy because Iran does not publish a shipbuilding invoice or a public line-item budget for a single hull, and open reporting rarely pins down what was installed as government-furnished gear versus shipyard-supplied equipment. The spread comes from scope. Hull steel and shipyard labor, propulsion, sensors, weapons integration, spares, documentation, and midlife upgrades can be counted together or kept in separate buckets, depending on how a navy books procurement and how much of the combat system is imported versus locally produced.

TL;DR: Public proxies come from peer programs and a clearly stated scope.

Unit here is one guided-missile frigate priced per hull and per major yard period. The proxy moves with combat-system scope, the spares package, and whether modernization is rolled into the headline number or funded years later.

Important numbers

Jump to sections

• IRIS Dena proxy build range of $335 million to $1.2 billion per hull, using a low-end frigate benchmark and a high-end frigate benchmark discussed below.
• Type 31 reporting described an average production figure of £250 million per ship, with the overall program framed at £2 billion and £1.25 billion value to the prime contractor in a Type 31 contract report.
• X-Rates lists a May 2025 monthly average of 1.335654 U.S. dollars per pound on its monthly average table.
• CRS summarized Constellation-class procurement in the $1.1 billion to $1.2 billion band per ship in the Nov 2024 CRS update.

Benchmarks navies publish

Outside Iran, the cleanest anchors come from public budget books, parliamentary papers, and shipyard milestone notes. A recent program update is a good sanity check for pacing and industrial capacity, even when it does not itemize every subsystem cost, such as a Feb 2026 Type 31 milestone update.

Cost proxy math Using a published £250 million per-ship production figure and the May 2025 monthly average of 1.335654 U.S. dollars per pound yields about $334 million because £250 million times 1.335654 equals $333.9 million, which rounds to about $335 million. On the high end, the Constellation-class procurement band runs to about $1.2 billion per ship, so a public proxy bracket for a frigate replacement build lands around $335 million to $1.2 billion per hull, with the gap explained by combat-system scope, testing, and integration.

Program	Public figure	Unit	What it covers
U.K. Type 31	£250 million	Per ship	Reported production figure tied to a fixed program scope
U.S. Constellation class	$1.1 billion to $1.2 billion	Per ship	Procurement totals that can bundle integration and testing
Italy frigate upgrades	€2.4 billion	15 years	Modernization and sustainment funding rather than new-build procurement

What this is in plain terms

Dena is a state-operated frigate, built to patrol, escort, and show the flag beyond Iran’s coast. It is commonly grouped with the Mowj program in English-language reporting, and it is discussed as a military platform rather than a commercial vessel. That matters because there is no public bill of sale, no catalog configuration, and no disclosed weapons package that can be priced like a consumer product. It also is not a destroyer with a heavier area air-defense loadout, and it is not an offshore patrol vessel built around endurance and light armament. Those role differences shape what “replacement” means and which peer programs are fair comparisons.

When people search for a number, they are usually trying to compare it with peer frigate programs or estimate replacement scope after a loss. That middle-ground role is why electronics integration and missile fit can swing the proxy far more than basic steelwork. No invoice exists. Rumors fill the gap.

Labor and hardware split

Shipbuilding is a mix of labor hours and high-value equipment. The hull and machinery side covers steelwork, welding, piping, paint, and propulsion, and it is shaped by yard throughput, rework, and supply timing for engines, gearboxes, and generators. The other big bucket is the combat system, radar, launchers, missiles, electronic warfare, and the test program that proves everything talks to everything. That mix is why two frigates with similar size can land in very different spending bands when one is loaded with newer sensors, denser missile stocks, and more complex integration.

Iran’s accounting is opaque, and outsiders rarely know what was imported, fabricated locally, or substituted under constraints. That is why any single hull-only dollar figure is speculation. A proxy range works best when it is tied to a defined scope statement, such as whether the number includes initial spares, training, and the first major yard period, or whether those costs sit elsewhere in the budget.

Design churn and rework

Change orders are the shipyard version of a contractor coming back for a revised scope. On modern frigates, a late change can be driven by weight growth, power margins, cooling, or a radar fit that needs different cabling runs. A U.S. watchdog review shows how design maturity can collide with schedule and cost, as described in a May 2024 GAO review of the Constellation-class program.

Even when a navy signs a fixed-price deal, the paperwork still has to handle new drawings, test failures, and late parts substitutions. Those changes show up as contract modifications, schedule slips, or capability tradeoffs, and they can swing the total far more than raw steel cost. One visible example is a contract modification notice that cited a $554 million adjustment for a follow-on U.S. frigate, which shows how totals move even after a baseline deal is signed.

Mini cases that differ

The Dena name reached wider headlines after reporting and analysis around a sinking off Sri Lanka and the legal framing of naval warfare. One accessible place where the event and context are discussed is a Just Security analysis. After a loss, the question shifts from “what did it cost” to “what would it take to replace,” and the replacement answer depends on whether the goal is a hull-only rebuild or a full combat-system replacement package.

Three common cost questions show up in practice. A replacement memo after a loss needs a new-build hull plus the sensors and missiles that were fitted, not scrap value. A refit decision at midlife is a yard-capacity question, since dry-dock time and parts pipelines can dominate the schedule and add labor costs. A cross-navy comparison for policy debate works best when it uses public peer figures as bookends and then describes capability differences, rather than forcing a single conversion that hides what is included and what is excluded.

Hidden costs after launch

Sustainment is where navies spend quietly. Parts, planned maintenance, midlife upgrades, and dockyard periods can run for decades, and sanctions or export controls can complicate logistics and spares. Crew training, software updates, and electronics obsolescence also push spending over time, even when the shipyard work looks stable on paper. A ship that deploys far from home can also burn through engines and consumables faster, which raises the tempo of maintenance events and replacement parts.

Italy offers a clean public illustration of how large those tails can be. Reuters described a €2.4 billion frigate maintenance and modernization plan over 15 years in a Dec 2025 parliament document story, so €2.4 billion divided by 15 years works out to about €160 million per year as a simple annual average for that program.

Worked example proxy build

This method does not claim a true build price for the Iranian ship. It builds a public bracket using published peers, then spells out what is excluded so readers can stop repeating a single “one true number.” The starting point is writing down the unit you mean. Is it hull-only, or hull plus sensors and missiles, or a full deployable package with spares and training, or a life-cycle number that includes major yard periods?

A simple bookend method uses a low-cost frigate program and a higher-cost frigate program, then treats the gap as capability and integration. The result is a bracket that is honest about uncertainty because each endpoint has a public anchor and the assumptions are visible. The bracket does not include fuel, crew pay, or years of operating cost unless you state that you are switching to life-cycle framing.

1. Pick a low-end peer build number that is publicly stated and has a defined ship count and scope.
2. Pick a higher-end peer procurement band that includes combat-system integration and testing.
3. State the exclusion list up front, munitions loads, spares packages, fuel, and decades of sustainment.

Who this cost makes sense for

A proxy helps when you are checking a viral claim about a military loss, or when you want a budget-language comparison across navies that publish procurement totals. U.S. context is easier when you also look at nuclear submarine budgets and aircraft carrier price tags because it shows where frigates sit in the fleet’s spending stack. Weapons and training rounds sit outside many hull budgets, so a shipyard figure can look low. A single line item like Mk 48 torpedo pricing shows how a weapons buy can change the story without changing the steel.

Tie any number you repeat to the unit you mean, per ship build, per yard period, or per year of sustainment. That one sentence is usually the difference between a careful estimate and a misleading headline number.

Takeaways

• No public invoice exists for the Iranian frigate.
• A public peer bracket lands around $335 million to $1.2 billion per hull, depending on scope.
• Combat-system integration can move totals more than basic steelwork.
• Modernization and sustainment can rival procurement over time.
• Always state the unit and what is excluded before repeating a number.

FAQs

Is there an official IRIS Dena contract price?

No public contract award or budget line has been published with a single build price for that hull.

Why do U.S. and U.K. figures look so different?

They can include different items and sit in different accounting systems, so comparisons only work when the scope is matched.

Does a warship’s cost include weapons?

Sometimes, but missiles and ammunition are often bought under separate programs, which is why a hull figure can mislead.

How should I quote a number responsibly?

State the unit, cite the public document, and say what is excluded, then avoid turning a proxy into a fact.